In the field of production of tertiary amines, side products such as monomethyl dialkylamine are formed particularly in production of dimethyl monoalkylamine by reacting an alcohol with dimethylamine in the presence of a catalyst, thus causing a reduction in yield. To solve this problem, JP-A 2001-151733 for example discloses a process for producing a tertiary amine at a high yield by suppressing side products with a combination of a catalyst and specific reaction conditions.
In the conventional techniques such as those described above, those skilled in the art have produced tertiary amines under general stirring conditions in this field. That is, a correlation of the gas flow number (NA) and agitating power ratio (Pg/P0), which indicates a mixed state of liquid and gas, is disclosed in FIG. 20-14 on page 902 in “Kagaku Kogaku Binran” (Chemical Engineering Handbook), revised 5th edition, published on Apr. 15, 1992, pp. 901-902 and edited by The Society of Chemical Engineers, Japan (SCE). There is also a disclosure wherein the agitating power ratio is practically 0.6 or more.